Engineer - Rubberbands

Rubberband StrengthOne of the requirements for engineer is to make a catapult. This requires the use of a rubber band or two, or a piece of tire inner tube. The rubber band is "elastic" and it stretches, but then returns to it's original shape. Before using materials in building, engineers must know the characteristics. Does it expand or contract? Is it weak or strong? Does it burn or not?

You can try an experiment to learn more of the characteristics of rubber bands and other elastic material. Get a collection of different sized rubber bands. Measure them for length, width and thickness (if you can). Make a chart that shows this information and mark each rubber band clearly so you know which is which. (Using colored rubberbands is best.)

Rubberband

Original

Stretched

Length

Width

Thickness

Length

Width

Thickness

With each rubber band, attach one end to a cup hook that is screwed into a board. Attach the other end to a known weight. How far down does each rubber band stretch? Does its thickness change? Does its width change? Which rubberband is the strongest? Which rubberband is the weakest? How can you tell?